(CINCINNATI) — A video released by the Cincinnati Zoo and Botanical Garden shows five newborn cheetah cubs being cared for after they were delivered in a rare cesarean section.

The cubs are in critical care, the zoo announced Friday in a press release. Zoo veterinarians performed the C-section on the cheetahs’ 5-year-old mother, named Willow, last week, according to the zoo.

The cubs’ immune systems have not developed well enough yet to ward off infections because they do not have access to Willow’s breast milk as she recovers from the surgery.

“The cubs were born under difficult circumstances,” said Mark Campbell, the Director of Animal Health at the Cincinnati Zoo. “For puppies and kittens, the vast majority of their passive immunity comes from their mom’s milk.”

The litter includes three male cubs and two female cubs, according to the zoo. For the past 10 days, they’ve required around-the-clock care and bottle feedings every three hours.

The baby cheetahs will remain in the nursery for the next eight to 12 weeks, the zoo said.

Cheetahs are endangered species, with their population shrinking from 100,000 in 1900 to an estimated 9,000 to 12,000 living today, the zoo said in the release.